In a point-to-multipoint service such as MBMS, data is transmitted from a single source entity to multiple recipients. Transmitting the same data to multiple recipients allows network resources to be shared. The MBMS bearer service offers two modes, a Broadcast Mode and a Multicast Mode. A reference architecture to support MBMS is shown in FIG. 1.
PS (Packet Switched) Domain functional entities such as GGSN (Gateway GPRS (General Packet Radio Service) Support Node), SGSN (Serving GPRS Support Node), UTRAN (UMTS (Universal Mobile Telecommunications System) Terrestrial RAN (Radio Access Network)), GERAN (GSM (Global System for Mobile communication) EDGE (Enhanced Data rates for Global Evolution) RAN), and UE (User Equipment) provide an MBMS Bearer Service. In a bearer plane, this service provides delivery of IP Multicast datagrams from a Gi reference point to UEs with a specified Quality of Service. In a control plane, this service provides mechanisms for managing an MBMS bearer service activation status of UEs (in the case of multicast mode), outsourcing authorization decisions to an MBMS User Service (i.e. to a BM-SC (Broadcast Multicast Service Centre) (in the case of multicast mode), providing control of session initiation/termination by the MBMS User Service and managing bearer resources for distribution of MBMS data (in the case or multicast and broadcast modes).
A particular instance of the MBMS Bearer Service is identified by an IP Multicast Address and an APN Network Identifier.
The boundary of the MBMS Bearer Service are Gmb and Gi reference points as shown in FIG. 1. The former provides access to control plane functions and the latter a bearer plane.
A functional entity, the Broadcast Multicast Service Centre (BM-SC), provides a set of functions for MBMS User Services. BM-SC functions for different MBMS User Services may be supported from the same or different physical network elements. The BM-SC provides functions for MBMS user service provisioning and delivery. It may serve as an entry point for content provider MBMS transmissions, used to authorize and initiate MBMS Bearer Services within the PLMN and can be used to schedule and deliver MBMS transmissions.
The UE supports functions for the activation/deactivation of the MBMS bearer service. Once a particular MBMS bearer service is activated, no further explicit user request is required to receive MBMS data although the user may be notified that data transfer is about to start. The UE supports security functions as appropriate for MBMS.
The UE should, depending on terminal capabilities, be able to receive MBMS user service announcements, paging information (non MBMS specific) and support simultaneous services (for example the user can originate or receive a call or send and receive messages whilst receiving MBMS video content). An MBMS Session Identifier contained in the notification to the UE enables the UE to decide whether it needs to ignore the forthcoming transmission of MBMS session (e.g. because the UE has already received this MBMS session).
The role of the SGSN within the MBMS architecture is to perform MBMS bearer service control functions for each individual UE and to provide MBMS transmissions to UTRAN/GERAN. The SGSN provides support for intra-SGSN and inter-SGSN mobility procedures. Specifically this requires the SGSN to store a user-specific MBMS UE context for each activated multicast MBMS bearer service and to pass these contexts to the new SGSN during inter-SGSN mobility procedures. The SGSN establishes Iu and Gn bearers shared by many users upon receiving a session start from the GGSN. Likewise, the SGSN is arranged to tear down these bearers upon instruction from the GGSN.
The role of the GGSN within the MBMS architecture is to serve as an entry point for IP multicast traffic as MBMS data. Upon notification from the BM-SC the GGSN requests the establishment of a bearer plane for a broadcast or multicast MBMS transmission. Further, upon BM-SC notification the GGSN is adapted to tear down the established bearer plane. Bearer plane establishment for multicast services is carried out towards those SGSNs that have requested to receive transmissions for the specific multicast MBMS bearer service. The GGSN may receive MBMS specific IP multicast traffic and route this data to the proper GTP tunnels set-up as part of the MBMS bearer service. The GGSN may also provide features that support the MBMS bearer service that are not exclusive to MBMS.
The current standard defines method and approach to establish MBM services for point to multipoint data transmission for a single MBM service to an MBMS user. However, the prior art handling of MBM services involves disadvantages as follows.
Present MBM services must be activated or deactivated before or after using an MBM service. In the light of the current mechanism, when a user intends to use an MBM service, the user will notify his intention via MM (Man Machine) interface and the UE will send a request IGMP (Internet Group Management Protocol) Join to the network for activating the MBM service. When the user desires to stop receiving the MBM service, he will leave the service by indicating this to the UE, which will then send a request IGMP Leave to the network for deactivating the MBM service.
As the UE may activate tens of MBM services the same time, it may become quite tedious to indicate the joining and leaving the desired services one by one to the UE. Moreover, according to the prior art, activation of tens of MBM services also means tens of MBMS PDP (Packet Data Protocol) contexts per UE which burdens network resources.